1. Preheat oven to 400 degrees F. Trim stems off 3 medium eggplants (2 1/2 to 3 lbs. total) and cut each lengthwise for a total of 24 to 32 slices. Brush the tops with 2 Tbs. olive oil. Bake on 2 large baking sheets (overlapping as needed) until very tender, 25 to 30 minutes.
2. In a large bowl, combine 20 oz. part-skim ricotta cheese, 1/3 cup grated Parmesan, 2 eggs, 6 thinly sliced scallions (white and light green parts), 1/2 tsp. kosher salt, and 1 lb. frozen chopped spinach (defrosted, liquid squeezed out).
3. Using a 24-oz. jar tomato-basil sauce, spread 1/4 cup sauce into each of two 8x8-inch pans. Scoop 2 to 3 Tbs. ricotta mixture onto one end of an eggplant slab, roll it up and tuck it in a pan. Repeat until all the rollatini are divided between the pans. Pour remaining tomato sauce over the top and scatter with 1 1/2 cups shredded mozzarella, dividing it evenly. Bake until bubbling, 30 minutes. Let stand 10 minutes before serving.
4. Serve one pan hot from the oven.Eat It Again!
5. Cool the second pan and wrap in aluminum foil. Refrigerate for up to three days, or freeze for up to three months. Reheat straight from fridge, covered, at 400 degrees F until hot, about 30 minutes or 65 minutes from frozen; remove foil for the last 15 minutes.Swap the Veggies
6. Use four to five zucchini (about 3 lbs.) instead of the eggplant.